test(cloudflare): Add e2e test for MCPAgent with DurableObject instrumentation

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/.gitignore

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+.wrangler

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/package.json

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+{
+  "name": "cloudflare-mcp-agent",
+  "version": "0.0.0",
+  "private": true,
+  "scripts": {
+    "deploy": "wrangler deploy",
+    "dev": "wrangler dev --var \"E2E_TEST_DSN:$E2E_TEST_DSN\"",
+    "build": "wrangler deploy --dry-run",
+    "typecheck": "tsc --noEmit",
+    "cf-typegen": "wrangler types",
+    "test:build": "pnpm install && pnpm build",
+    "test:assert": "pnpm typecheck && pnpm test:dev && pnpm test:prod",
+    "test:prod": "TEST_ENV=production playwright test",
+    "test:dev": "TEST_ENV=development playwright test"
+  },
+  "dependencies": {
+    "@modelcontextprotocol/sdk": "^1.29.0",
+    "@sentry/cloudflare": "file:../../packed/sentry-cloudflare-packed.tgz",
+    "agents": "0.11.9",
+    "zod": "^4.3.6"
+  },
+  "devDependencies": {
+    "@cloudflare/workers-types": "^4.20260426.0",
+    "@playwright/test": "~1.56.0",
+    "@sentry-internal/test-utils": "link:../../../test-utils",
+    "typescript": "^6.0.3",
+    "wrangler": "^4.86.0"
+  },
+  "volta": {
+    "extends": "../../package.json"
+  }
+}

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/playwright.config.ts

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+import { getPlaywrightConfig } from '@sentry-internal/test-utils';
+const testEnv = process.env.TEST_ENV;
+
+if (!testEnv) {
+  throw new Error('No test env defined');
+}
+
+const APP_PORT = 38788;
+
+const config = getPlaywrightConfig({
+  startCommand: `pnpm dev --port ${APP_PORT}`,
+  port: APP_PORT,
+});
+
+export default config;

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/src/env.d.ts

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+interface Env {
+  E2E_TEST_DSN: string;
+  MCP_AGENT: DurableObjectNamespace;
+}

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/src/index.ts

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+import * as Sentry from '@sentry/cloudflare';
+import { McpAgent } from 'agents/mcp';
+import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
+import * as z from 'zod';
+
+class MyMCPAgentBase extends McpAgent<Env, unknown, Record<string, unknown>> {
+  #mcpServer = new McpServer({
+    name: 'cloudflare-mcp-agent',
+    version: '1.0.0',
+  });
+
+  get server() {
+    return Sentry.wrapMcpServerWithSentry(this.#mcpServer);
+  }
+
+  async init(): Promise<void> {
+    this.#mcpServer.registerTool(
+      'my-tool',
+      {
+        title: 'My Tool',
+        description: 'My Tool Description',
+        inputSchema: {
+          message: z.string(),
+        },
+      },
+      async ({ message }) => {
+        const span = Sentry.getActiveSpan();
+
+        await new Promise(resolve => setTimeout(resolve, 500));
+
+        if (span) {
+          span.setAttribute('mcp.tool.name', 'my-tool');
+          span.setAttribute('mcp.tool.extra', 'from-mcpagent');
+          span.setAttribute('mcp.tool.input', JSON.stringify({ message }));
+        }
+
+        return {
+          content: [
+            {
+              type: 'text' as const,
+              text: `Tool my-tool: ${message}`,
+            },
+          ],
+        };
+      },
+    );
+  }
+}
+
+export const MyMCPAgent = Sentry.instrumentDurableObjectWithSentry(
+  (env: Env) => ({
+    dsn: env.E2E_TEST_DSN,
+    environment: 'qa',
+    tunnel: `http://localhost:3031/`,
+    tracesSampleRate: 1.0,
+    sendDefaultPii: true,
+    debug: true,
+    transportOptions: {
+      bufferSize: 1000,
+    },
+  }),
+  MyMCPAgentBase,
+);
+
+export default Sentry.withSentry(
+  (env: Env) => ({
+    dsn: env.E2E_TEST_DSN,
+    environment: 'qa',
+    tunnel: `http://localhost:3031/`,
+    tracesSampleRate: 1.0,
+    sendDefaultPii: true,
+    debug: true,
+    transportOptions: {
+      bufferSize: 1000,
+    },
+  }),
+  MyMCPAgent.serve('/mcp', { binding: 'MCP_AGENT' }),
+);

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/start-event-proxy.mjs

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+import { startEventProxyServer } from '@sentry-internal/test-utils';
+
+startEventProxyServer({
+  port: 3031,
+  proxyServerName: 'cloudflare-mcp-agent',
+});

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/tests/index.test.ts

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+import { expect, test } from '@playwright/test';
+import { waitForRequest } from '@sentry-internal/test-utils';
+
+test('sends spans for MCP tool calls via MCPAgent (DurableObject)', async ({ baseURL }) => {
+  const mcpToolWaiter = waitForRequest('cloudflare-mcp-agent', event => {
+    const transaction = event.envelope[1][0][1];
+    return (
+      typeof transaction !== 'string' &&
+      'transaction' in transaction &&
+      transaction.transaction === 'tools/call my-tool'
+    );
+  });
+
+  // Step 1: Initialize the MCP session
+  const initResponse = await fetch(`${baseURL}/mcp`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+      Accept: 'application/json, text/event-stream',
+    },
+    body: JSON.stringify({
+      jsonrpc: '2.0',
+      id: 0,
+      method: 'initialize',
+      params: {
+        protocolVersion: '2024-11-05',
+        capabilities: {},
+        clientInfo: {
+          name: 'test-client',
+          version: '1.0.0',
+        },
+      },
+    }),
+  });
+
+  expect(initResponse.status).toBe(200);
+  const sessionId = initResponse.headers.get('Mcp-Session-Id');
+  expect(sessionId).toBeTruthy();
+
+  // Step 2: Send initialized notification
+  await fetch(`${baseURL}/mcp`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+      Accept: 'application/json, text/event-stream',
+      'Mcp-Session-Id': sessionId!,
+    },
+    body: JSON.stringify({
+      jsonrpc: '2.0',
+      method: 'notifications/initialized',
+    }),
+  });
+
+  // Step 3: Call the tool with the session ID
+  const response = await fetch(`${baseURL}/mcp`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+      Accept: 'application/json, text/event-stream',
+      'Mcp-Session-Id': sessionId!,
+    },
+    body: JSON.stringify({
+      jsonrpc: '2.0',
+      id: 1,
+      method: 'tools/call',
+      params: {
+        name: 'my-tool',
+        arguments: {
+          message: 'hello from MCPAgent test',
+        },
+      },
+    }),
+  });
+
+  expect(response.status).toBe(200);
+
+  const mcpData = await mcpToolWaiter;
+  const mcpEvent = mcpData.envelope[1][0][1];
+
+  expect(mcpEvent.contexts?.trace?.trace_id).toBe(mcpData.envelope[0].trace.trace_id);
+  expect(mcpEvent.contexts?.trace).toEqual({
+    trace_id: expect.any(String),
+    parent_span_id: expect.any(String),
+    span_id: expect.any(String),
+    op: 'mcp.server',
+    origin: 'auto.function.mcp_server',
+    data: expect.objectContaining({
+      'sentry.origin': 'auto.function.mcp_server',
+      'sentry.op': 'mcp.server',
+      'mcp.method.name': 'tools/call',
+      'mcp.tool.name': 'my-tool',
+      'mcp.tool.extra': 'from-mcpagent',
+      'mcp.tool.input': '{"message":"hello from MCPAgent test"}',
+    }),
+  });
+});

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/tsconfig.json

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+{
+  "compilerOptions": {
+    "target": "es2021",
+    "lib": ["es2021"],
+    "jsx": "react-jsx",
+    "module": "es2022",
+    "moduleResolution": "Bundler",
+    "resolveJsonModule": true,
+    "allowJs": true,
+    "checkJs": false,
+    "noEmit": true,
+    "isolatedModules": true,
+    "allowSyntheticDefaultImports": true,
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "skipLibCheck": true,
+    "types": ["@cloudflare/workers-types/experimental"]
+  },
+  "exclude": ["test"],
+  "include": ["src/**/*.ts"]
+}

dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/wrangler.jsonc

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+{
+  "$schema": "node_modules/wrangler/config-schema.json",
+  "name": "cloudflare-mcp-agent",
+  "main": "src/index.ts",
+  "compatibility_date": "2025-03-21",
+  "compatibility_flags": ["nodejs_compat"],
+  "durable_objects": {
+    "bindings": [
+      {
+        "name": "MCP_AGENT",
+        "class_name": "MyMCPAgent",
+      },
+    ],
+  },
+  "migrations": [
+    {
+      "tag": "v1",
+      "new_sqlite_classes": ["MyMCPAgent"],
+    },
+  ],
+}